(i) Prime factor of 5 = 5

Prime factor of 8 = 2 x 2 x 2

No common prime factor

H.C.F. of 5 and 8 = 1

(as both the number are co-prime)

(ii) Prime factor of 24 = 2 x 2 x 2 x 3

Prime factor of 49 = 7 x 7

No common prime factor, number are co-prime.

H.C.F. of 24 and 49 = 1.

(iii) Prime factor of 40 = 2 x 2 x 2 x 5

Prime factor of 60 = 2 x 2 x 3 x 5

Prime factor of 80 = 2 x 2 x 2 x 2 x 5

Common prime factor = 2 x 2 x 5

H.C.F. of 40, 60 and 80 = 2 x 2 x 5 = 20

(iv) Prime factor of 48 = 2 x 2 x 2 x 2 x 3

Prime factor of 84 = 2 x 2 x 3 x 7

Prime factor of 88 = 2 x 2 x 2 x 11

Common prime factor of 48, 84 and 88 = 2 x 2

H.C.F. of 48, 84 and 88 = 2 x 2 = 4

(v) Prime factor of 12 = 2 x 2 x 3

Prime factor of 16 = 2 x 2 x 2 x 2

Prime factor of 28 = 2 x 2 x 7

Common prime factor between 12, 16 and 28 = 2 x 2

H.C.F. of 12, 16 and 28 = 2 x 2 = 4